migrate.sh 支持 DSN 与可选客户端路径

生产的宝塔机器把数据库配置放在一个 Go 风格的 IM_DB_DSN 里，而不是 compose
的那组 MYSQL_* 变量；同机自带的 mysql 客户端又缺 caching_sha2_password 插件，
连不上 MySQL 8.4。脚本原先把主机写死成 compose 的服务名 mysql，在非 Docker
环境用不了。

现在 MYSQL_HOST/MYSQL_PORT/MIGRATIONS_DIR/MYSQL_CLIENT 都可覆盖，未设置
MYSQL_USER 时从 IM_DB_DSN 解析；显式的 MYSQL_* 仍然优先。默认值保持 compose
原样，Docker 路径行为不变。

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

im/deploy/migrate.sh

@@ -1,18 +1,42 @@
 #!/bin/sh
 set -eu
 
-mysql_args="--host=mysql --user=${MYSQL_USER} --database=${MYSQL_DATABASE} --default-character-set=utf8mb4 --batch --skip-column-names"
+# Defaults match the compose topology; the BaoTa host runs MySQL outside Docker
+# on the loopback, so host and port are overridable there.
+mysql_host="${MYSQL_HOST:-mysql}"
+mysql_port="${MYSQL_PORT:-3306}"
 
-until MYSQL_PWD="${MYSQL_PASSWORD}" mysql ${mysql_args} --execute "SELECT 1" >/dev/null 2>&1; do
+# The BaoTa host keeps one Go-style DSN instead of the compose MYSQL_* set, and
+# its bundled client cannot speak caching_sha2_password, so the 8.x client has
+# to be selectable. Explicit MYSQL_* values still win.
+if [ -z "${MYSQL_USER:-}" ] && [ -n "${IM_DB_DSN:-}" ]; then
+  dsn="${IM_DB_DSN}"
+  MYSQL_USER="${dsn%%:*}"
+  rest="${dsn#*:}"
+  MYSQL_PASSWORD="${rest%@tcp(*}"
+  hostport="${rest##*@tcp(}"
+  hostport="${hostport%%)*}"
+  mysql_host="${hostport%%:*}"
+  mysql_port="${hostport##*:}"
+  database="${dsn##*)/}"
+  MYSQL_DATABASE="${database%%\?*}"
+fi
+mysql_bin="${MYSQL_CLIENT:-mysql}"
+
+mysql_args="--host=${mysql_host} --port=${mysql_port} --user=${MYSQL_USER} --database=${MYSQL_DATABASE} --default-character-set=utf8mb4 --batch --skip-column-names"
+
+until MYSQL_PWD="${MYSQL_PASSWORD}" "${mysql_bin}" ${mysql_args} --execute "SELECT 1" >/dev/null 2>&1; do
   sleep 2
 done
 
-MYSQL_PWD="${MYSQL_PASSWORD}" mysql ${mysql_args} --execute "CREATE TABLE IF NOT EXISTS schema_migrations (version VARCHAR(255) NOT NULL PRIMARY KEY, checksum CHAR(64) NOT NULL, applied_at DATETIME(3) NOT NULL DEFAULT CURRENT_TIMESTAMP(3)) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4"
+MYSQL_PWD="${MYSQL_PASSWORD}" "${mysql_bin}" ${mysql_args} --execute "CREATE TABLE IF NOT EXISTS schema_migrations (version VARCHAR(255) NOT NULL PRIMARY KEY, checksum CHAR(64) NOT NULL, applied_at DATETIME(3) NOT NULL DEFAULT CURRENT_TIMESTAMP(3)) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4"
 
-for file in /migrations/*.sql; do
+migrations_dir="${MIGRATIONS_DIR:-/migrations}"
+
+for file in "${migrations_dir}"/*.sql; do
   version="$(basename "${file}")"
   checksum="$(sha256sum "${file}" | awk '{print $1}')"
-  existing="$(MYSQL_PWD="${MYSQL_PASSWORD}" mysql ${mysql_args} --execute "SELECT checksum FROM schema_migrations WHERE version='${version}'" 2>/dev/null || true)"
+  existing="$(MYSQL_PWD="${MYSQL_PASSWORD}" "${mysql_bin}" ${mysql_args} --execute "SELECT checksum FROM schema_migrations WHERE version='${version}'" 2>/dev/null || true)"
   if [ -n "${existing}" ]; then
     if [ "${existing}" != "${checksum}" ]; then
       echo "Migration checksum mismatch: ${version}" >&2
@@ -22,6 +46,6 @@ for file in /migrations/*.sql; do
     continue
   fi
   echo "Applying: ${version}"
-  MYSQL_PWD="${MYSQL_PASSWORD}" mysql ${mysql_args} < "${file}"
+  MYSQL_PWD="${MYSQL_PASSWORD}" "${mysql_bin}" ${mysql_args} < "${file}"
-  MYSQL_PWD="${MYSQL_PASSWORD}" mysql ${mysql_args} --execute "INSERT INTO schema_migrations(version,checksum) VALUES('${version}','${checksum}')"
+  MYSQL_PWD="${MYSQL_PASSWORD}" "${mysql_bin}" ${mysql_args} --execute "INSERT INTO schema_migrations(version,checksum) VALUES('${version}','${checksum}')"
 done